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I am sorry to hear about this situation.
If you are a juror, then the penalty for not showing up when being called for jury duty is being found in contempt of court, punishable by fine and/or incarceration pursuant to California Code of Civil Procedure Section 209. This normally means a few hours in jail to scare you and/or a fine, or a threat thereof. If you have a specific psychological condition making it very hard for you to serve, then someone in your situation wants to get a letter from your psychologist/psychiatrist ASAP even if the appointment is near the date of the time to appear, and they can send a LETTER to the Court the same day in many cases, which confirms that you are unable to serve and typically, you would not have to show (or show just to produce the letter).
The problem is that contempt of court may mean not only a fine, but also jail time and then you'd still have to serve, so this does need to be taken care of. The appointment with a doctor does seem to be the solution, however. They CAN send that letter after seeing you even once.
If you are the Defendant, then not showing up for trial means the Court will issue a warrant for your arrest, and the authorities may arrest you to bring you back to court to stand trial.
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